Google funded and built a wastewater treatment plant in Georgia—and it uses …

Google is using toilet water to cool its data center in western Georgia.

In 2007, when Google first opened its massive computing center in Douglas County, Georgia, it cooled the facility's equipment using the same water that's pumped into the pipes of local homes. But at some point, the search giant realized that the water used by its evaporative cooling system needn't be clean enough to drink.

On Thursday, Google revealed that it's now working with the Douglasville-Douglas County Water and Sewer Authority to cool the facility with 100 percent recycled water. "When the residents of the county take showers and flush their toilets, they're helping to cool our data center," Joe Kava, the man who runs Google's data center operations and construction team, tells Wired.

The company may save some money in the long term with its recycled water. But according to Kava, that's not the primary aim. In partnering with the Sewer Authority, Google is no longer putting the same strain on the area's natural water supply—and it's making sure it can ride out a drought. "The finances make sense, but over a much longer period of time. It was really about being environmentally responsible and securing our supply if there was rationing of potable water," Kava says. "You don't want to contribute to any fresh water shortage."

Google uses a similar system at its data center in Saint-Ghislain, Belgium—where it reuses water from a nearby industrial canal—and both efforts are part of larger movement toward "free cooling." In using local water and outside air to cool data centers, companies such as Google, Facebook, and Microsoft can reduce their dependency on power-hungry mechanical chillers. Like Google, these companies say they do this to reduce the damage that their massive computing facilities do to the planet.

The Douglasville-Douglas County Water and Sewer Authority (WSA) operates a water treatment plant that, yes, scrubs sewer water from local houses and returns it to Georgia's Chattahoochee River. But according to Google, the WSA is now diverting about 30 percent of that sewer water to a second treatment plant built and paid for Google. After it's cleaned at this second facility—which sits about five miles west of the WSA plant—the water is streamed to the company's data center.

The water is then used to run the data center's evaporative cooling system. Basically, Google pushes hot air from its servers into the much cooler water, and most of this water is then evaporated into the Georgia air as it cascades down large cooling towers. Any remaining water is moved into another treatment plant, where Google disinfects it, removes various minerals, and returns it to the Chattahoochee.

How Google fits into the Georgia system

Google

According to Michael Patton, the deputy director of water and waste water operations for the WSA, Google's setup does indeed remove a significant burden from the county's natural water supply. Google turned on its treatment center on in December 2008, Patton says, and the following summer—peak water season—there was an enormous drop in consumption across the system.

"It's a win-win for both us," Patton tells Wired, "and for the community too."

Google still operates some sort of electrical cooling system in the data center—the company won't go into detail, reluctant to reveal its "secret sauce"—but this is only used on days when the sewer water is too hot to cool the machines. "There is some chiller capacity here, but certainly not enough to run the entire facility on chillers," says Kava. "They're just used for what we call ‘heat shaving.' During those certain hours of the years when cooling towers by themselves are not sufficient, we can turn the chillers on." In Georgia, he says, these are only needed for a few hours in the middle of hot summer days.

In Belgium, where the climate is much cooler, Google can operate its data center without any chillers at all, and the same goes for its facility on the southern coast of Finland, where it cools servers using water from the Baltic Sea.

Microsoft and Facebook are also running data centers sans chillers. But methods vary. At its new center in Prineville, Oregon, for instance, Facebook cools its server room using the outside air coming off the high desert.

Old-school data center players have long used free cooling as well. At one of its "co-location" data centers in San Jose, California—a place where myriad businesses operate servers—Equinix uses the outside air to cool its server rooms, though it still relies heavily on chillers as well. According to Jerry Collier, senior director of International Business Exchange (IBX) operations at Equinix, the company can only embrace so much free cooling because many of its customers still insist that their servers run at extremely low temperatures.

Traditionally, data centers operate at temperatures between about 60 and 80 degrees Fahrenheit, but Google and others have realized that computing hardware can reliably run at much higher temperatures. This has opened the door to much more extensive free cooling—while putting a whole new spin on the flushing toilet.

The line "the water used by its evaporative cooling system needn't be clean enough to drink" is a bit confusing to me. East of the MIssissippi it's very common for wastewater to be treated to be turned into potable water that is delivered to homes to drink. (For some reason, this is politically unpopular in states like California where they could make most use of the practice.) I guess Google's treatment plant could treat it but not quite up to potable standards, but I suspect that environmental standards require that any water being treated to be returned to the river or released into the air like that has to be cleaned to potable standards.

The line "the water used by its evaporative cooling system needn't be clean enough to drink" is a bit confusing to me. East of the MIssissippi it's very common for wastewater to be treated to be turned into potable water that is delivered to homes to drink. (For some reason, this is politically unpopular in states like California where they could make most use of the practice.) I guess Google's treatment plant could treat it but not quite up to potable standards, but I suspect that environmental standards require that any water being treated to be returned to the river or released into the air like that has to be cleaned to potable standards.

No, that's all about a completely separate issue. What it says is that water used in a cooling system doesn't need to be clean enough to drink and that's not confusing at all (no one is drinking it).

What they were previously doing was attaching their cooling system to the main water supply as if it was a domestic tap and using water that was clean enough to drink to cool their servers. You don't need to do that. You can use any water as long as it's cool enough.

Kind of disappointed that an article about environmental impact makes no reference to thermal pollution. http://en.wikipedia.org/wiki/Thermal_pollution Or really any more thorough explanation of all the inputs and outputs besides Google's infographic.

So, instead of going through all the trouble of cleaning the water before it goes back in to the river, they could create a wetland, let the water flow through it and it would come out of the other end almost as clean as tap water. Maybe they don't have enough acreage, but it's a solution that should be used more.

The article is not so much about enviromental impact as it is about a kind of interesting way that Google is handling their cooling needs. I believe that Google is doing this more for the stability of their cooling supply and for the eventual cost savings than for the enviromental impact. That's just the feel-good part of the story.

Tuborg wrote:

Kind of disappointed that an article about environmental impact makes no reference to thermal pollution. http://en.wikipedia.org/wiki/Thermal_pollution Or really any more thorough explanation of all the inputs and outputs besides Google's infographic.

So what I'm getting from this is that the water initially treated by the local authorities is dumped into a river, even though it's not clean enough to cool Google's data centre.

Not at all. Instead of 100% of wastewater going into the county's treatment facility and then into the river and Google using tap water to cool their data center, 70% of wastewater goes to the county's treatment facility and then into the river, and 30% goes to Google's treatment facility, after which it is used to cool their data center.

Kind of disappointed that an article about environmental impact makes no reference to thermal pollution. http://en.wikipedia.org/wiki/Thermal_pollution Or really any more thorough explanation of all the inputs and outputs besides Google's infographic.

Presumably the cooling towers mentioned in the article are used to cool off the water leaving the data center before it is discharged into the river.

So what I'm getting from this is that the water initially treated by the local authorities is dumped into a river, even though it's not clean enough to cool Google's data centre.

Not at all. Instead of 100% of wastewater going into the county's treatment facility and then into the river and Google using tap water to cool their data center, 70% of wastewater goes to the county's treatment facility and then into the river, and 30% goes to Google's treatment facility, after which it is used to cool their data center.

That's not quite right, 100% of the wastewater goes to the county treatment facility and 30% of the water leaving the facility for the river goes to Google's system of treatment facilities and cooling towers.

Still not sure why data center's don't use ground loop cooling. Drill a bunch of holes down 300 or so feet put some tubing in and let the earth do the majority of cooling. Seems like a no-brainer. Maybe it is done and just never mentioned.

Still not sure why data center's don't use ground loop cooling. Drill a bunch of holes down 300 or so feet put some tubing in and let the earth do the majority of cooling. Seems like a no-brainer. Maybe it is done and just never mentioned.

It's not as easy as it sounds and hasn't that many advantages. While ground loop cooling is more efficient than chillers, evaporative cooling is better. With ground loop cooling you have to consider ground temperature (which can be quite high), so you still might need some kind of heat pump. Also, with facilities this size, ground capacity is an issue, environmental permits as well. Evaporative cooling as used by google is nearly passive and scales easily. Actually it's the same technique used by nuclear power stations. All it needs is a reliable water source, and google has obviously found one.

The line "the water used by its evaporative cooling system needn't be clean enough to drink" is a bit confusing to me. East of the MIssissippi it's very common for wastewater to be treated to be turned into potable water that is delivered to homes to drink. (For some reason, this is politically unpopular in states like California where they could make most use of the practice.) I guess Google's treatment plant could treat it but not quite up to potable standards, but I suspect that environmental standards require that any water being treated to be returned to the river or released into the air like that has to be cleaned to potable standards.

Au contraire... (Or is that "eau contraire"? :^)

Hoidy-"toidy" Orange County now has the worlds largest toilet-to-tap system in the world.

one important thing about google's strategy here is that by scattering data centers all over the planet, if one gets too hot for evaporative cooling alone, they can move the load to another data center where the weather is cooler, then back again when the weather changes. this allows them to size the chillers even smaller and use them even less often than local considerations alone would demand.

quite interesting. i've always been a fan of low resource data center cooling. i wonder if we could apply some of this to solve other problems like fresh water supply. could they for example, pump in salt water from (source) then evaporate the water and collect the salt to sell on the market and make some money? using a primary loop to move heat from servers to secondary saltwater loop (think reactor like). could they then take that evaporated water, and using the air or shade, cool/condense it into fresh water to package/pipe and sell/give away to nations that need the fresh water for drinking/farming?

My personal feeling is that this is simply the cheapest (long term) way to cool their systems. If municipal water is metered and payed for, as it likely is, then using this cheaper (possibly free) waste water is cheaper long term. The alternative is direct use of river/ground water, which is usually more expensive to clean than the already partially treated water from the waste plant (which is generally returned to the river/drainage cleaner than it was when taken out.). As mentioned by the PR flak it also protects against rationing due to drought. This kind of thinking is common in industry and the PR guys come in to give it that smiley faced enviro theme. (Systems that use waste heat in large industrial furnaces are called "economisers" for a reason, but they're also enviro friendly.) Despite what he says I think economics are the real majn factor in this decision, but everyone also gets to pat themselves on the back (and smell their own farts...SouthPark style!) over the "improved" enviro impact.That's not to say it isn't environmentally friendly, I'm just fairly sure that it's cheaper long term.

I'm happy to read about anyone using non-potable water for anything. It drives me insane that it isn't required in the US that all new homes and buildings don't use drinking water for flushing toilets, washing machines, etc. Everyone agrees that water is a precious resource. So why are we still using drinking-quality (potable) water to flush our crap down the toilet!? (Apologies for that being slightly off-topic.)

It drives me insane that it isn't required in the US that all new homes and buildings don't use drinking water for flushing toilets, washing machines, etc. Everyone agrees that water is a precious resource. So why are we still using drinking-quality (potable) water to flush our crap down the toilet!?

I for one would love to have my ass splashed with hepatitis A every time I sit on the toilet. And I think coating my bath towel with E. coli so I can transfer it to my face post showering is an excellent idea as well.

It drives me insane that it isn't required in the US that all new homes and buildings don't use drinking water for flushing toilets, washing machines, etc. Everyone agrees that water is a precious resource. So why are we still using drinking-quality (potable) water to flush our crap down the toilet!?

I for one would love to have my ass splashed with hepatitis A every time I sit on the toilet. And I think coating my bath towel with E. coli so I can transfer it to my face post showering is an excellent idea as well.

Gross but enlightening. 100 internets for setting the record straight and 50 for the snarky remark.